The strut-type hybrid system can be made in different geometric shapes, which are affected by: the number and arrangement of struts, the shape and position of the cable in relation to the girder, and the size and shape of the cross-section of the girder. When choosing a system, all the listed parameters can vary geometrically, which has consequences on the behaviour of the girder when carrying the load by directly affecting the change in the stiffness of the system. In addition to the geometric parameters, the stiffness of the hybrid system is affected by variations in the properties of the incorporated materials and their mutual relations. In this paper, based on a detailed parametric analysis, the principles of design, the choice of materialisation, and the possibility of further optimisation of the persistent-type hybrid systems are given, with the aim of additionally increasing the load capacity and reducing the deformability. The results of this research are presented in the form of general expressions and diagrams, which can be applied with sufficient accuracy in practice when choosing the form and materialisation of the hybrid system, as well as the possibility of further optimisation of the system by applying pre-stressing. Using the example of external pre-stressing of a glued laminated timber girder, with the assumption of ensuring the lateral stability of the system, the results of the analysis of the behaviour of such a system under load in real conditions, i.e. the influence of the environment and changes in material properties, are given.

Plastic waste is a significant environmental and ecological problem that requires urgent action. Indeed, plastic waste pollutes our oceans, rivers, and lakes, harming aquatic life and marine ecosystems. Plastic debris also poses a threat to terrestrial wildlife, as animals can mistake plastic for food or become entangled in it, leading to injury or death. In addition, plastic production requires fossil fuels, leading to greenhouse gas emissions contributing to climate change. That is why recycling plastic waste is an important step towards reducing the environmental impact of plastic and creating a more sustainable future. The present work is part of this approach, and it aims to investigate the effects of the size of the plastic fibers and their percentages on the performances of Hot Mix Asphalt (HMA) in road pavement. Marshall Tests were carried out on the reference asphalt (without adding plastic) and the asphalt containing plastic waste in order to highlight the effect of these additives on the mechanical performance of asphalt mixtures. It has been found that the addition of PET plastic waste considerably improves the mechanical properties of the HMA. The findings revealed that additives composed of plastic fibres of size ranging between 0.125 and 1.25 mm give the best results in terms of Marshall’s Stability and Flow, by acting as reinforcement to the bitumen-aggregate mixtures. Furthermore, the optimum plastic content was found to be about 3.75% by weight of bitumen. It can be noted that the proposed solution fits very well with sustainable development.

Architect Nikola Dobrović is best known in Serbia for his only constructed building in Belgrade, the complex of the State Secretariat of National Defense (DSNO), better known as the General Staff, today an endangered cultural heritage and a crumbling building with an uncertain future. However, his short-term engagement as the head of the Urban Planning Institute of the Republic of Serbia from 1946-1947, and his later professorship at the Faculty of Architecture University of Belgrade, are equally significant for Belgrade and Serbia. Documents testifying to the post-war period of his work are scattered in several places: in the Urban Planning Institute of Belgrade, the Museum of Science and Technology, the Historical Archive of Belgrade, and the rare publications can only be found in a few libraries in Serbia. In the course of his short-term work on New Belgrade, Dobrović provided several conceptual projects and sketches for New Belgrade within the Urban Planning Institute: the perfomance square, road schemes and the urban planning solution of the zone between the Palace of the Federation and the Railway Station - today's Central Zone of New Belgrade. Finally, at different stages of his career, Dobrović also designed individual objects, such as the project for the Faculty of Electrical Engineering and the building of the Central Committee of the Communist Party of Yugoslavia, which remained in the domain of 'paper architecture', unbuilt, and which provides an insight into the way he thought about the process of urban and spatial planning, through the positioning of builidngs which would've generated the character of their immediate and distant surroundings.